Research On Fine Modeling Of Oblique Photography And Monitoring Method Of Building Deformation

As the construction goals of smart water conservancy,smart city and digital Earth are constantly proposed,key technologies such as big data,cloud services,Internet of Things and sensors are rapidly iterated,and building model information(BIM)has become the development trend of the construction industry.With its visualization,coordination,simulation,optimization,mapping,it is widely used in the planning and design,construction,operation and management of large civil engineering industry.On the basis of meeting the basic visual digital information carrier model,BIM technology pays more attention to the information integration and coordination between various units at different stages of the project,dynamic and static simulation,simulation and cost management at each stage of building construction,so as to make the project expression more detailed and avoid the information island at each stage.In the future,the combination with big data,the Internet of Things and other high-tech,is the only choice to meet the smart project,digital twin.Laser scanning technology and photogrammetry technology,as two different means of reverse modeling,can quickly acquire X,Y,Z coordinates,RGB color and other data information of each point on the surface of the building through their respective acquisition methods and quickly construct the real three-dimensional model of the target scene,which can not only reflect the real world objectively and truly,but also have three-dimensional geographic information.With the rapid development of economic and infrastructure construction in our country,more and more buildings are springing up like bamboo shoots after a rain.In order to ensure its safety in each construction stage of whole life cycle of operation,need to aim at the building or engineering site(mountain,slope),periodical deformation monitoring.After understanding and learning the reverse modeling and deformation monitoring with objectivity,this paper combines the 3D model of real tilt photography with deformation monitoring,analyzes the factors affecting tilt photography by constructing tests,and uses the multi-period high-precision tilt photography model and automatic servo robot to analyze the changes of monitoring targets.And relying on hydraulic engineering projects to carry out engineering measurement,can reflect the whole and local change law of the building from the point and surface,providing a rapid detection method for the traditional deformation detection.The main research work of this paper is as follows:1.The basic theory and method of three-dimensional reconstruction of oblique photography,the constitution of oblique photogrammetry system,the field acquisition and internal processing methods and processes of image data are introduced.Based on the analysis of the main factors affecting the oblique photography modeling,the layout of image control points,image ground resolution,image overlap rate and later supplementary shooting were taken as the objects,and their influence on the model accuracy was analyzed through the construction of experiments.Finally,the influence analysis of the accuracy of oblique photogrammetry and the highest accuracy model of this experiment were obtained.2.The automatic servo measuring robot is used to build an automatic deformation monitoring system.The model constructed by tilt photography is compared with the specific point data monitored by the deformation monitoring system,and the difference change value of multi-period data is used to judge whether the building has deformation.Through the experiment to simulate the deformation that may occur in the construction or management process of buildings,it can be divided into the following two types: 1.The building is not deformed;2.The building has a deformation.3.Based on the test results,the deformation monitoring method adopted in the test was applied to a water conservancy hub in Henan Province,and the model point data generated by the image modeling collected by the test was compared and analyzed with the data of the automatic monitoring system.The results showed that:The error of the checkpoint data collected by the tilt photography model and monitoring system is small and belongs to the instrument error,which can be used in the fast monitoring task of the building during operation.